Global Dynamics and Exchange Kinetics of a Protein on the Surface of Nanoparticles Revealed by Relaxation-Based Solution NMR Spectroscopy.
J Am Chem Soc
; 138(18): 5789-92, 2016 05 11.
Article
em En
| MEDLINE
| ID: mdl-27111298
ABSTRACT
The global motions and exchange kinetics of a model protein, ubiquitin, bound to the surface of negatively charged lipid-based nanoparticles (liposomes) are derived from combined analysis of exchange lifetime broadening arising from binding to nanoparticles of differing size. The relative contributions of residence time and rotational tumbling to the total effective correlation time of the bound protein are modulated by nanoparticle size, thereby permitting the various motional and exchange parameters to be determined. The residence time of ubiquitin bound to the surface of both large and small unilamellar liposomes is â¼20 µs. Bound ubiquitin undergoes internal rotation about an axis approximately perpendicular to the lipid surface on a low microsecond time scale (â¼2 µs), while simultaneously wobbling in a cone of semiangle 30-55° centered about the internal rotation axis on the nanosecond time scale. The binding interface of ubiquitin with liposomes is mapped by intermolecular paramagnetic relaxation enhancement using Gd(3+)-tagged vesicles, to a predominantly positively charged surface orthogonal to the internal rotation axis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Espectroscopia de Ressonância Magnética
/
Proteínas
/
Nanopartículas
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article